NTA Abhyas JEE Main2020Chemistryd and f Block ElementsPractice
The oxidation number is changed in which of the following case?
Options
- AS O 2 gas is passed into C r 2 O 7 2 - / H +
- BAqueous solution of C r O 4 2 - is acidified
- CC r O 2 C l 2 is dissolved in N a O H
- DC r 2 O 7 2 - solution is made alkaline .
Correct answer
A. S O 2 gas is passed into C r 2 O 7 2 - / H +
Step-by-step solution
a C r 2 O 7 2 - + 6 + S O 2 + 4 + 2 H + → 2 C r 3 + + 3 + 3 S O 4 2 - + 6 + H 2 O b 2 C r O 4 2 - + 6 + 2 H + → C r 2 O 7 2 - + 6 + H 2 O c   CrO 2 Cl 2 +6   +   2NaOH → Na 2 CrO 4 d C r 2 O 7 2 - + 6 + 2 O H - → 2 C r O 4 2 - + 6 + H 2 O